1. Field
One embodiment of the invention relates to an optical disc such as a DVD which serves as a medium to store digitized video and audio works such as movies and music. It further relates to an optical disc apparatus which reads information recorded on the optical disc and to an optical disc manufacturing method. Still further, it covers a digital work publication recorded on a recording medium.
2. Description of the Related Art
<Outline of the DVD Standard>
One known type of optical disc for storing digital images is the Digital Versatile Disc (DVD), which has been widely used all over the world mainly for storing and delivering movie content (digital work publications). DVD is a format created by the DVD Forum, which is open to the public as the DVD Book (refer to the World Wide Web: dvdforum.org). DVD has also been determined in international standards and JIS. Here, the international standard ISO/IEC 16448 for 120 mm DVD-ROM, one of the DVD physical formats, will be briefly explained. Moreover, ECMA-267 is a document associated with the international standards.
There are four types of 120 mm DVD-ROM: single-sided single layer, single-sided dual layer, double-sided single layer, and double-sided dual layer. In delivery of an accumulation of contents of movies and the like, two types of single-sided discs are mainly used: one is a single-sided single layer DVD disc (4.7 GB) and the other is a single-sided dual layer DVD disc (8.54 GB). However, recently, the single-sided dual layer DVD disc has accounted for 60% of the total.
On the other hand, the development of a disc whose capacity is larger than that of the aforementioned DVD (referred to as the existing DVD) has been desired. This comes from a desire to store High-Definition (HD) images on a single disc (temporarily referred to as a next-generation DVD).